July 12, 2015 Recycling No Comments
how is e-waste recycled

Due to the heavy burden that electronic waste

(e-waste) can cause to human health and to the environment due to toxic components such as heavy metals, responsible recycling of these products is a necessity in an increasingly technology-driven world.

Have you ever wondered what happens to your old televisions or computers once you turn them in to be recycled? While many companies continue to send these defunct gadgets overseas, leading to a number of undesirable impacts, many companies are now recycling electronic products using responsible and sustainable processes.

 

The E-Waste Recycling Process

Because electronic waste contains a variety of materials, including plastics, glass, and metals, recycling e-waste requires several steps to recover these resources in the most efficient manner.

In general, both manual labor and automation are involved during the electronic waste recycling process. The use of automated equipment during the recycling process helps to efficiently recover reusable materials, eliminates hazardous waste, and protects workers and the environment¹.
 

  1. Picking: Electronic items are manually sorted, and components that should not be shredded or crushed are removed by hand, such as batteries, UPS battery systems, toner cartridges, and fluorescent lights¹.
  2.  

  3. Shredding: An Initial Size Reduction step shreds the electronic items into small 100mm size pieces, and a Secondary Size Reduction step further breaks down materials into even smaller fragments that are well suited for the separation process. Any dust extracted during this process is disposed of using environmentally-friendly methods².
  4.  

  5. Magnetic Removal: Steel and iron fragments are removed by magnets².
  6.  

  7. Metallic and Nonmetallic Separation: Other metals, such as aluminum, copper, and brass are separated from non-metallic materials, such as glass and plastic. Separation occurs through Eddy currents, optical identification, and magnets².
  8.  

  9. Separation by Water: Plastic and glass are separated by using water². Lead-containing glass may be sent to lead smelters to be used to make new products such as batteries, new CRTs, and x-ray shields. Plastics are separated by color and sold to plastic recyclers³.



Once all of the raw materials have been separated, they can be sold as commodities to recyclers and manufacturers to make new electronic devices or other items.

Circuit boards are ground up and smelted, the gases are captured, and the metals can be sold as raw commodities. Wood from older television model cabinets may be chipped and used to be burned as biofuel³.

 

The CRT Recycling Process

Because the Cathode Ray Tubes (CRTs) that are present in computer monitors and old televisions contain large amounts of toxins such as lead that can be harmful to human health and to the environment, recycling these devices requires a separate process from most other electronics².

  1. Monitor Body and Cathode Ray Separated: The front of the monitor or television body must be removed in order to access the CRT within, and the outer shell of the monitor or television must be recycled with other e-waste².
  2.  

  3. Size Reduction: The CRT tubes and screens are shredded into tiny pieces, and the glass dust is removed using environmentally-friendly methods².
  4.  

  5. Metal Removal: Using magnets, iron and steel are removed from the broken pieces, and then aluminum and copper is removed by passing the rest of the material through Eddy currents².
  6.  

  7. Washing: Any remaining glass fragments are cleaned to remove oxides, phosphors, and dust extracts, leaving clean glass to be sorted one last time².
  8.  

  9. Glass Sorting: The leaded glass is separated from unleaded glass. Both types of glass can be used to manufacture new screens². Lead-containing glass may also be sent to lead smelters to be used to make new products such as batteries, new CRTs, and x-ray shields³.

 

The best e-waste recycling systems consist of self-contained recycling processes after the initial manual separation step, as well as self-contained collection of raw materials to be shipped to manufacturers. This ensures the highest level of protection for both human health and the environment³.

 


References

¹ http://goo.gl/TAOPMk
² http://goo.gl/MFnin4
³ http://www.recycleworks.org/ewaste/ewaste_process.html

Written by Greentumble Editorial Team